In other approaches, a file system is usually established in a disk. To increase an access speed, an MMAP manner is usually used to access the file system. A file may be mapped onto virtual space of a process; then data is read from a hard disk into a cache, and a mapping entry is generated from a cache page and added to a process page table. Therefore, the process can directly access the file by accessing the process page table.
With the development of novel non-volatile memory (NVM) technologies represented by a phase change memory (PCM), a resistive random access memory (RRAM), a magnetic random access memory (MRAM), and a ferroelectric random access memory (FRAM), an access speed of a novel NVM is increased greatly. In addition, the novel NVM can be addressed by byte, and data is written into the non-volatile memory in units of bits. Therefore, the novel NVM can be used as a memory, an NVM storage medium is managed in a page-based manner, and the NVM is directly accessed by a central processing unit (CPU). In the prior art, an NVM-based memory file system is also provided. If a memory is an NVM, and if the file system is still accessed in the MMAP manner, an access process is complex, and a cached page table entry needs to be added to the process page table. Therefore, load on the process page table is increased.